1. Field of the Invention
The field of this invention relates to a threaded, removable collared winch yoke for installing or removing threaded electrical power riser pipes.
Such a yoke also relates to the field of utility electrical pipes and power supply services.
Further, the field of the invention relates to a removable, threaded hollow yoke centered for winch lifting of threadable riser pipes for above-ground feed of electrical power.
2. Description of Prior Art
In the utility field of supplying power services to consumers, a major problem relates to the assembly of the sectioned riser pipes that one sees next to utility poles. These riser pipes bring power from the pole base to the upper pole area. The nature of the riser pipe problems and prior art deficiencies are discussed in an enclosed incentive award description and account of the present invention in the CMP Weekly Update of Aug. 14, 1997. This Update article describes the invention, and actual units have been in use by Central Maine Power ("CMP")--the Awarding entity.
In the Power Company world such as CMP, underground utilities are increasing in numbers and whenever electrical power must emerge to the daylight from its underground run, a sectioned riser pipe is necessary. The riser pipe houses the service, or power, wire from the base of the pole to the top of the pole. Such riser pipe sections, when threaded together, are thus placed along side utility poles for local power distribution. These riser pipes are heavy, bulky and extremely hard to handle.
Since several threaded sections of heavy pipe are required for a full length rise, each individual section of riser pipe must be threaded to the next by threaded collars. Each new section must be suspended by a rope, chain or sling to be threaded to the previous upright section. The problem of long recognition was how to suspend such sections while threading them to the previously installed section.
A conventional prior art way of handling such riser sections involved slings or "off-center" rope lifts. Because the lifting point of the prior art was off-center, workers often are troubled trying to keep the pipe vertical for proper threading of one riser section to the next. Then, to make matters worse, as each section is being threaded, the rope or sling twists around the pipe, further complicating the job and risking damage both to the workers and to the threads.
Cross-threaded pipes and injuries have occurred. Thus, this prior art approach is both wasteful and dangerous, as well.
Installation of such risers, must also accommodate a pull cord that is inserted through the riser before lifting. Such a pull cord has a free upper end for the workers use and, in turn, is connected to an electrical power cable at the lower end. That pull cord, after the riser sections are joined together, is pulled through the assembled sections in order to retrieve and advance the electrical power lines which must also be lifted through the installed riser pipes. In the prior art this cord became entangled in the rope slings as the twisting was taking place.
Each riser installation involves several pipe sections which must be screw-threaded together, often by utility workers in a lift basket. Being both bulky and heavy, such risers pose a hazard to workers as they attempt to thread one riser section to another riser section by the use of threaded collars which span and join a pair of upright sections.
This invention markedly reduces the prior art hazards and facilitates connection of several riser sections. The pull cord entanglement problem has also been solved. The invention thus, for the first time, creates a solution to a problem that--though recognized--has long remained unsolved by the prior art.
A search of the prior art has revealed various patents, several of which are only of peripheral relevance and others that are greatly disadvantageous when compared to the unusual benefits of the subject invention.
The specific areas of search included:
Class 294 sub-classes 90, 91, 82.14, 82.15 and 82.16 PA1 Class 24 sub-classes 317 and 24.
The search turned up several patents of interest. The patents found for review are:
______________________________________ 4,221,252 September 9, 1980 Bruce 2,519,288 August 15, 1950 Roberson 4,188,141 February 12, 1980 Stoot 14,253 January 23, 1917 Wigle 1,436,621 November 21, 1922 Coultas 1,798,296 March 31, 1931 Yerkes 2,149,938 March 19, 1936 Hickman ______________________________________
A brief discussion of this art follows: Taking the patents of the search in the order listed above:
U.S. Pat. No. 4,221,252 Sep. 9, 1980 Bruce
Bruce is simply a well known shackle apparatus. The primary emphasis of the Bruce patent concerns the manner of locking nut 5 to the shaft 6. Plastic locking pins and seating housings, as best shown in Bruce FIG. 2, for example, are employed. No threaded collar is suggested, much less such a threaded collar being incorporated into and made part and parcel of the entire lifting yoke.
U.S. Pat. No. 2,519,288 Aug. 15, 1950 Roberson
Roberson is an oil well hook that has little relevance unless studied upside down and then it still is not suggestive of the invention. Some pages are missing from the enclosed copy of Roberson, but from what can be understood, the Roberson hook seems to require a pressurized fluid cylinder which ultimately drives a locking dog 25 into one of a series of peripheral locking grooves 27 as shown in FIG. 3.
U.S. Pat. No. 4,188,141 Feb. 12, 1980 Stoot
The Stoot patent discloses a butt hook that is useful in logging operations and has a centrally located bore 16, FIG. 2, that houses a choker cable 11. Cable 11 is affixed with an end ferrule 17. The disclosure of this Stoot reference relates to different functions and achieves those different functions in a different way. It has only peripheral relevance to the invention.
U.S. Pat. No. 14,253 Jan. 23, 1917 Wigle
The Wigle patent is again involved with well casings. Wigle provides both a rotational and a swivel movement of hook 4. In the Wigle reference please note that sleeve 15, FIG. 2, has located therein a spring 10 which is formed around the shaft 17 and at the end of this centrally located shaft is positioned a double-sided ball bearing raceway formed by upper and lower disks 20 and 21. No threaded collar is involved nor is there any suggestion of the novel principles of this invention.
U.S. Pat. No. 2,149,938 Mar. 19, 1936 Hickman
Housing 1 of the Hickman reference has a partially open area whereas in Wigle it is completely blocked. Hickman housing 1 is rectangular in shape and is open at the bottom and at one side for receiving what are called sucker rods in well bores. A Hickman clevis 2 is held in place on the top of housing 1 by a nut/bolt 4 having a thrust bearing 5 to provide for rotational movement. Apparently, the sucker rods such as 14 (shown in dashed lines) are rectangular shaped at the upper end and those ends are adapted to fit within opening 7 in housing 1. Such sucker rods are solid and do not compare favorably with open threaded hollow collars or riser pipes.
U.S. Pat. No. 1,436,621 Nov. 21, 1922 Coultas
U.S. Pat. No. 1,798,296 Mar. 31, 1931 Yerkes
These two references do not seem to add anything to the above-noted art, but are listed for sake of thoroughness.
In summary, none of the well casing hook lifts (including Wigle or Hickman discussed above) would serve or suggest the functions of the present invention, since none of them have an opening therethrough such as a hollow threaded collar, which opening receives the pull cord or electrical power cables that must be threaded through the riser sections.
Moreover, none of the references teach or suggest a set screw fastener to hold a threaded collar affixed to a riser pipe for hoisting and vertical alignment when threading one riser section to another upright riser section. Being centered and held in a vertically plumb position by the invention, threading of one riser section to another is easily accomplished whereas in the "off-center" prior art it was a difficult and dangerous undertaking.